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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #07-0225 ([Packaging Applications for Dangerous Goods, LLC] [Mr. David Gluntz])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Packaging Applications for Dangerous Goods, LLC

Individual Name: Mr. David Gluntz

Location State: OH Country: US

View the Interpretation Document

Response text:

February 25, 2008



Mr. David Gluntz                                                                                 

Packaging Applications for Dangerous Goods, LLC

3583 Blackbottom Court,

Columbus, OH 43221-4501


Ref. No. 07-0225


Dear Mr. Gluntz:


This responds to your November 28, 2007 email and subsequent telephone conversations requesting clarification of the general design requirements for DOT portable tanks under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).  Specifically, you ask whether installing a "bleed off valve" assembly as a component of the pressure relief system for a DOT 51 portable tank is prohibited and requires a special permit to install.


Your enclosed sketch indicates the bleed off valve assembly would be installed between the pressure gauge/tell-tale indicator and the pressure relief device to allow for the safe removal of vapors trapped in the void space should a leak occur in the frangible disc.


It does not appear that the installation of the bleed off valve assembly involves a modification of the DOT 51 portable tank that would invalidate the ASME U stamp.  Therefore, the bleed off valve assembly installed as a component of the pressure relief system as shown in your sketch is not prohibited and does not require a special permit to install.  However, we highly recommend the use of good engineering practices (e.g., a leakage test) when installing the assembly.  A report of the installment and any testing must be made a part of the records for the portable tank.


I hope this information is helpful.  Please contact us if you require additional assistance.





Hattie L. Mitchell

Chief, Regulatory Review and Reinvention.

Office of Hazardous Materials Standards



Regulation Sections

Section Subject
178.275 Specification for UN Portable Tanks intended for the transportation of liquid and solid hazardous materials